Date:         Tue, 28 Mar 2006 05:08:38 -0500
Reply-To:     Gerhard Hellriegel <ghellrieg@T-ONLINE.DE>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Gerhard Hellriegel <ghellrieg@T-ONLINE.DE>
Subject:      Re: Problem with scope of macro variables

without following the thread:
unfortunately there are no real good ways of returning values from macros.
There are no referential parameters to return any results from a macro call,
so I think there is no really easy way to avoid global variables.

If you have a macro like:

%let a=outside;
%macro test(a);
  %put inside: &a;
  %let a=inside;
%mend;
%test(&a);
%put the result is: &a;

you see that the passed argument &a is not changed. There is only a passing
of values into the macro, but not out. At some places it is possible to work
with a kind of function-call, like:

%let a=outside;
%macro test(b);
  %put &b;
  %let b=inside;
  &b;
%mend;
%let a=%test(&a);

%put the result is: &a;




On Tue, 28 Mar 2006 02:34:21 -0500, SUBSCRIBE SAS-L Katja
Gla=?ISO-8859-1?Q?=DF?= <cayburn@GMX.DE> wrote:

>I see the point. I whish I could redesign the system without global macro
>variables. Unfortunately the system is really complex, and consists of
>quite a lot of macros. Even the environment is not that simple, so "work"
>can't be used for this, and it must support multiple users and some more
>things to consider ;) .
>At least this problem appeard the first time in 5 years of use. I will
>just update the global macro variable if this variable really has been
>changed, so this will also reduce the appearancy. To get the error in the
>log is a good indicator, that the user of the system has to change the
>name of a global macro variable.
>Now I know, then when I create a system from the scratch, I won't work
>with setting and resetting of global macro variables.
>Hopefully in some later SAS versions more weird things are solved.
>Thanks for the discusstion.
>From my side everything is fine as well.
>
>Regards,
>Katja :-)